Mild MPP+ exposure-induced glucose starvation enhances autophagosome synthesis and impairs its degradation

Sakamoto Shuichiro

Miyara Masatsugu

Sanoh Seigo

Ohta Shigeru

Kotake Yaichiro

Scientific Reports

Parkinson’s disease (PD) is a prevalent neurodegenerative disorder, mainly characterised by the progressive loss of dopaminergic neurons. MPP+ has been widely used as a PD-related neurotoxin, and their reports suggested the several hypotheses for neuronal cell death. However, most of these hypotheses come from the studies about the acute MPP+ exposure. We previously revealed that mild MPP+ exposure (10 and 200 μM), which induces gradual cell death, impairs autophagosome degradation at 48 h. In the present study, we further investigated the specific events of mild MPP+ exposure and revealed that mild MPP+ exposure causes the cell death through glucose starvation, but not acute toxic model (2.5 and 5 mM). At 36 h after mild MPP+ exposure, autophagosome synthesis was enhanced owing to glucose starvation and continued to enhance until 48 h, despite impaired autophagosome degradation. Inhibition of autophagosome synthesis reduced mild MPP+-induced cell death. In conclusion, we clarified that glucose starvation-enhanced autophagosome synthesis occurs at an earlier stage than impaired autophagosome degradation and is important in mild MPP+ toxicity.

eng

Nature Research

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[ISSN] 2045-2322

[DOI] 10.1038/srep46668

[DOI] https://doi.org/10.1038/srep46668